How do I set the default value for an optional argument in Javascript? [duplicate]
I am writing a Javascript function with an optional argument, and I want to assign the optional argument a default value. How can I assign it a default value?
I thought it would be this, but it doesn't work:
function(nodeBox,str = "hai")
{
// ...
}
Solution 1:
If str
is null, undefined or 0, this code will set it to "hai"
function(nodeBox, str) {
str = str || "hai";
.
.
.
If you also need to pass 0, you can use:
function(nodeBox, str) {
if (typeof str === "undefined" || str === null) {
str = "hai";
}
.
.
.
Solution 2:
ES6 Update - ES6 (ES2015 specification) allows for default parameters
The following will work just fine in an ES6 (ES015) environment...
function(nodeBox, str="hai")
{
// ...
}